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Performance
of 50 Completed ATP Projects
Status
Report - Number 2
NIST SP 950-2
Chapter
4 - Electronics, Computer Hardware & Communications
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Thomas
Electronics, Inc.
Flat Fluorescent
Lamps for Displays
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| Every
cockpit in a large airplane contains small windows that are mainly
used when the plane is on the ground. While flying, pilots see the
world not by looking out the windows, but by looking at the text and
images shown by instrument displays mounted on the walls of the cockpit.
The quality of these images bears directly on the quality of the flying. |
COMPOSITE
PERFORMANCE SCORE
(Based on a four star rating.)
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More-Visible Instrument
Displays for Safer Flying
Today, almost every
cockpit display uses cathode ray tube (CRT) technology. CRTs are a proven
technology, have a long history and are fabricated by Thomas Electronics
— which undertook this ATP project — for use in the manufacture
of cockpit displays. CRT displays, however, have a well-known drawback:
the surface is glass, and the view one gets through it depends on the
amount of light in the cockpit and the direction the light is coming from.
In some circumstances, such as bright sunlight, visibility of displays
may be seriously diminished.
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| Flat fluorescent
lamps for flat panel display backlighting, in a variety of sizes,
ranging from 1.5 inches to 12.5 inches on the diagonal. |
Creating a Flat Fluorescent
Lamp
Liquid-crystal displays
(LCDs) — the flat-panel displays used in notebook computers —
would be a good alternative to CRT displays. The drawback to LCDs, however,
is that their light source is not nearly bright enough for use in airplane
cockpits. This ATP project addressed that problem by developing the technology
needed to make a flat, bright fluorescent lamp for backlighting an LCD.
The new lamp would be about a quarter of an inch thick, have the same
length and width as the LCD, and be attached to its back.
In conventional fluorescent
lamps, a cathode discharges electrons that excite mercury vapor to emit
ultraviolet light that, in turn, induces the phosphor coating on the interior
of the lamp to glow white. Flat fluorescent lamps were not developed earlier
because of the difficulty in generating a bright plasma in the thin space
etween wide, flat sheets. Conventional cathodes are too inefficient to
create enough light for the color LCDs used in avionic displays. And although
barium dispenser cathodes (BDCs) are efficient enough for the task, they
were never used in the presence of mercury, which is believed to poison
the barium and quickly reduce both the efficiency and life span of the
device. Thomas solved the mercury problem with BDCs by using a new hollow-cathode
design that enabled the company to construct a truly flat fluorescent
lamp.
In addition, Thomas
introduced new materials to flat fluorescent lighting. The front of the
lamp is glass. But the back is hardier ceramic material and has all the
light-producing components embedded in it. The ceramic back enables the
lamp to withstand severe shock and vibration much better than if both
sides were glass. In addition, the thermal properties of the ceramic material
allow the lamp to operate at significantly higher temperatures than comparable
lamps made solely of glass. As a result, these new lamps can be used for
rugged flat-panel displays in applications such as military tanks.
Field Testing Underway
Follow-on research and development work is on track to meet the project’s
commercialization goal — the introduction into commercial and military
airplane cockpits of flat-panel displays containing the new fluorescent
lamp. To date, Thomas has invested more of its own money in the effort
than it received from ATP, and the work is beginning to pay off. The company
is completing a pilot production plant and has received orders for further
evaluation and field testing of the new technology from Optical Image
Systems, AlliedSignal, Honeywell, Litton Industries, Kaiser Electronics
and five other companies. The field testing must yield positive results
before the Federal
Aviation Administration will certify the flat-panel displays for use in
cockpits.
About 10,000 displays
are installed in airplane cockpits each year. Compared with CRT devices,
the new flat-panel displays will be more effective (they produce more
light), more reliable (the ceramic material is hardier than glass), and
less-costly (the ceramic material can be machined more easily than glass).
Ultimately, their use is expected to benefit aircraft passengers, who
will enjoy safer air travel because pilots have more-effective, more-reliable
instrument displays. It is also expected to benefit flat-panel display
manufacturers, aircraft manufacturers and airlines through cost reductions
and quality improvements.
Potential uses for
the flat-lamp technology include displays in military ground vehicles,
such as tanks. Displays in these applications must withstand greater extremes
in vibration, temperature, and other operating conditions than ordinary
displays. Three companies specializing in such displays have ordered flat-lamp
prototypes from Thomas.
ATP Bolsters U.S.
Technology
Without the ATP award, Thomas officials say, the company would not have
done the research and development work for this project. The company would
have struggled along with its conventional CRT technology and would have
stood virtually no chance of competing with other display-component suppliers,
all of which are foreign companies. In addition, the award helped Thomas
establish connections with scientists at Princeton University and form
alliances with contractors.
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Project
Highlights
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PROJECT:
To develop a high-efficiency electron source for fluorescent lighting
to enable a new class of efficient, bright, flat lamps with wide
applications in computer and instrument displays, high-definition
TV displays and wide-area ultraviolet light sources for industrial
use.
Duration: 2/1/1994 — 1/31/1997
ATP Number: 93-01-0109
FUNDING (in
thousands):
| ATP |
$718
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77%
|
| Company |
215
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23%
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| Total |
$933
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ACCOMPLISHMENTS:
Thomas developed the high-efficiency electron source needed to construct
flat fluorescent lamps, which was the goal of the project. The company
achieved the following:
- entered pilot
production of flat lamps for key customers in the U.S. display
industry;
- received
orders for further evaluation and field testing of the new technology
in cockpit applications from Optical Image Systems, AlliedSignal,
Honeywell, Litton Industries, Kaiser Electronics, and five other
companies; and
- placed prototypes
with three military contractors for rugged displays in tanks and
other ground vehicles.
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COMMERCIALIZATION
STATUS:
Current sales of prototypes and pilot models of flat fluorescent
lamps to avionics customers range from 30 to 50 units per month.
If customer tests prove the technology works for them, regular commercial
sales are expected to begin after the flat-panel displays have been
certified by the Federal Aviation Administration for use in cockpits.
OUTLOOK:
Full commercialization is expected after refinements to the technology
based on feedback from customers using prototype units. If the technology
is commercialized, its users — aircraft manufacturers, airlines
and their passengers — will benefit from brighter, more reliable
and cheaper backlights for flat-panel displays in airplane cockpits.
Composite
Performance Score:
COMPANY:
Thomas Electronics, Inc.
100 Riverview Drive
Wayne, NJ 07470
Contact:
Douglas Ketchum
Phone: (973) 696-5200
Number of employees: 251 at project start, 324 at the end
of 1997
Informal collaborator: Princeton University
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Return to Table
of Contents or go to next section.
Date created: April
2002
Last updated:
April 12, 2005
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